Fig. 8.
PRDM1 represses the expression of the Kv4.3 channel in dorsal root ganglion neurons. (A and B) Levels of Kv4.3 protein in ipsilateral lumbar 4 and lumbar 5 dorsal root ganglions on day 7 after chronic constriction injury or sham surgery from short hairpin RNA– or Scram-injected mice. Data are expressed as mean ± SD. *P < 0.05 versus the corresponding sham + Scram group, ##P < 0.01 versus the corresponding chronic constriction injury + Scram group. One-way ANOVA followed by post hoc Tukey test, F(3, 20) = 13.33, n = 6 per group. (C) Level of Kcnd3 mRNA in ipsilateral lumbar 4 and lumbar 5 dorsal root ganglions after microinjection of PRDM1 overexpression and green fluorescent protein into unilateral lumbar 4 and lumbar 5 dorsal root ganglions in mice. Data are expressed as mean ± SD. ** P < 0.01 versus the green fluorescent protein group by two-tailed unpaired t test, n = 6 per group. (D and E) Levels of Kv4.3 protein in ipsilateral lumbar 4 and lumbar 5 dorsal root ganglions after microinjection of PRDM1 overexpression and green fluorescent protein into unilateral lumbar 4 and lumbar 5 dorsal root ganglions in mice. Data are expressed as mean ± SD. ***P < 0.001 versus the green fluorescent protein group by two-tailed unpaired t test, n = 6 per group. (F) Schematic diagram of the Kcnd3 gene with the exon depicted as a black box. Primers for chromatin immunoprecipitation–quantitative polymerase chain experiments are shown as gray rectangles. (G) Chromatin from sham and injured dorsal root ganglions 7 days after chronic constriction injury was immunoprecipitated with an antibody specific for PRDM1 or immunoglobulin G as a negative control, followed by quantitative polymerase chain with primers specific for five different regions of the Kcnd3 gene, as illustrated in panel F. Data are expressed as mean ± SD. **P < 0.01, ***P < 0.001 versus the sham group by two-tailed unpaired t test, n = 3 repeats per group. Note that in most cases, the immunoglobulin G negative control has a very low percentage of input levels and is therefore not visible in most of the graphs. PRDM1, positive regulatory domain I–binding factor 1.